/*

 * Licensed to the Apache Software Foundation (ASF) under one

 * or more contributor license agreements.  See the NOTICE file

 * distributed with this work for additional information

 * regarding copyright ownership.  The ASF licenses this file

 * to you under the Apache License, Version 2.0 (the

 * "License"); you may not use this file except in compliance

 * with the License.  You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package com.bff.gaia.unified.sdk.extensions.sql.impl.utils;



import org.apache.calcite.rex.RexFieldAccess;

import org.apache.calcite.rex.RexInputRef;



import java.util.ArrayList;

import java.util.Collections;

import java.util.List;



/** SerializableRexFieldAccess. */

public class SerializableRexFieldAccess extends SerializableRexNode {

  private List<Integer> indexes = new ArrayList<>();



  public SerializableRexFieldAccess(RexFieldAccess rexFieldAccess) {

    indexes.add(rexFieldAccess.getField().getIndex());

    RexFieldAccess curr = rexFieldAccess;

    while (curr.getReferenceExpr() instanceof RexFieldAccess) {

      curr = (RexFieldAccess) curr.getReferenceExpr();

      indexes.add(rexFieldAccess.getField().getIndex());

    }



    // curr.getReferenceExpr() is not a RexFieldAccess. Check if it is RexInputRef, which is only

    // allowed RexNode type in RexFieldAccess.

    if (!(curr.getReferenceExpr() instanceof RexInputRef)) {

      throw new UnsupportedOperationException(

          "Does not support " + curr.getReferenceExpr().getType());

    }



    // curr.getReferenceExpr() is a RexInputRef.

    RexInputRef inputRef = (RexInputRef) curr.getReferenceExpr();

    indexes.add(inputRef.getIndex());



    Collections.reverse(indexes);

  }



  public List<Integer> getIndexes() {

    return indexes;

  }

}